
import java.util.*;
public class Main
{
    public static void main(String[] args)
    {
        Scanner in = new Scanner(System.in);
        int n = in.nextInt(), k = in.nextInt();
        long[] a = new long[n + 1];
        long[] b = new long[n + 1];
        for(int i = 1; i <= n; i++)
            a[i] = in.nextLong();
        for(int i = 1; i <= n; i++)
            b[i] = in.nextLong();
        int left = 1, right = 1;
        long hSum = 0, sSum = 0, hMax = 0, sMin = 0, begin = 0;
        while(right <= n) {
        // 进窗⼝
        hSum += a[right];
        sSum += b[right];
         // 出窗⼝
         while(right - left + 1 > k) {
             hSum -= a[left]; sSum -= b[left]; left++;
         }

         // 更新结果
         if(right - left + 1 == k) {
            if(hSum > hMax) {
                begin = left; hMax = hSum; sMin = sSum;
            } else if(hSum == hMax && sSum < sMin) {
                begin = left; sMin = sSum;
            }
        }
         right++;
        }
        System.out.println(begin);
    }
}

